A patient undergoing immunotherapy for a bee sting allergy experiences a sudden drop in blood pressure and difficulty breathing. Which mechanism primarily explains the patient's acute symptoms?

💡 Explanation

During anaphylaxis, pre-sensitized mast cells release histamine and other mediators systemically, causing vasodilation and bronchoconstriction. Therefore, systemic mast cell degranulation accounts for the symptoms, rather than T-helper cell proliferation or IgG production which are associated with long-term immune modulation.

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